海水中总氮的测定方法比较研究

通过标准曲线、检出限和测定范围、方法精密度、方法准确度、实际海水样品测定结果、加标回收率、分析效率和物料消耗这几方面比较了过硫酸钾氧化法、流动注射分析法和高温氧化-化学发光检测法这3种测定海水中总氮(TN)方法的优缺点。结果表明,流动注射分析法和高温氧化-化学发光检测法的测定范围更宽,精密度、准确度更好,3种样品的加标回收率达到96.2%~101%;高温氧化-化学发光检测法分析效率高、物料消耗少、节能环保,适用于一般海水样品的批量分析,且由于测定范围大,该法也适用于TN浓度较高的海水样品的批量分析,流动注射分析法因其较低的检出限更适用于TN浓度较低的海水样品的批量分析。     

海水、地面水中磷酸盐测定方法

以人工海水、纯水为介质 ,采用先加钼酸盐后加抗坏血酸进行显色 ,在 70 0 nm波长下测定校准曲线 ,线性较好且没有显著性差异 ,方法稳定 ,可同时测定海水和地表水无机磷、地表水总磷。检出限低于 0 .0 1 mg/L;测定天然水样 ,相对标准偏差5.1 %～ 0 .9% ;测定加标水样加标回收率为 95%～ 1 0 5% ;重复测定加标回收率相对标准偏差为1 .3%～ 2 .7% ;重复测定质控样品和标准样品误差范围 - 0 .0 0 2～ + 0 .0 0 5mg/L、- 0 .0 0 8～ +0 .0 0 4 mg/L、- 0 .0 8～ + 0 .0 0 7mg/L,相对标准偏差 0 .8%、1 .2 %、1 .3% ,精密度、准确度可满足方法要…     

利用DMA-80自动测汞仪直接测定海水中痕量汞

采用DMA-80自动测汞仪直接测定海水中的痕量汞,详细介绍了干燥时间、分解温度、释放温度等分析条件的优化选择。试验结果,方法在0.4～400ng范围内线性良好,检出限为2×10-5mg/L,方法操作简单,灵敏度高,结果准确。     

基体改进石墨炉原子吸收直接测定海水中的痕量重金属

较系统地研究了基体改进剂硝酸铵、磷酸二氢铵、硝酸钯等在测定海水中铜、铅、镉、铬的运用,建立了海水中重金属直接测定的方法并讨论了基体改进剂消除干扰的作用机理.方法用于测定北仑港近岸海域海水中的痕量元素,结果令人满意.     

ICP-MS/MS直接测定海水中12种痕量金属元素

建立一种采用电感耦合等离子体串联质谱 (ICP-MS/MS) 直接测定海水中12种元素的分析方法。采用标准加入法及配置超高基体进样系统实现基体匹配,应用ICP-MS/MS的多种分析模式测定海水中钒（V）、铬（Cr）、锰（Mn）、钴（Co）、镍（Ni）、铜（Cu）、锌（Zn）、砷（As）、钼（Mo）、镉（Cd）、铊（Tl）、铅（Pb）12种痕量元素。用该方法测定海水标准参考物质,结果准确。测定实际海水样品,加标回收率为85.0%~108%,相对标准偏差为1.5%~5.4%。12种元素的方法检出限为0.003~0.085 μg/L,定量下限为0.012~0.340 μg/L。该方法运行成本低,操作便捷,可作为实验室海水元素分析的常规检测方法。     

塞曼石墨炉原子吸收法测定土壤及其标样中8个元素

石墨炉原子吸收法测定土壤中的微量元素已较为普遍,但一些元素由于基体干扰难以直接测定,具有塞曼效应的仪器由于其扣除背景能力强,提供了直接测定的可能性。本文探讨了不同类型土壤标准物质中Co、Cr、Pb、Cd、Cu、Ni、As、Be直接测定的方法,Pb、Cd采用管内标准加入技术,As、Be用Ni(NO_3)_2,Al(NO_3)_2分别作基体改进剂直接测定,方法灵敏快速,变异系数在0.5～7.6％范围,加标回收率为88～112％。     

海水总磷高效快速测定方法的优化研究

海水总磷（TP）是海洋生态环境的重要监测指标，传统的海水TP测定方法为国标法——《海洋调查规范 海水总磷测定 过硫酸钾法》（GB/T 12763.4—2007），目前许多海域水体TP质量浓度均超出国标法的检测范围，在检测过程中需要进行稀释，过程烦琐且易影响测定结果的准确性，常用的其他方法也存在不适用于TP的快速连续测定且测定成本较高的问题。基于过硫酸根离子氧化磷化合物生成磷酸根离子的原理，探究海水TP测定的反应体系的影响因素，研究结果表明：过硫酸钾质量浓度为40 g/L，抗坏血酸质量浓度为54 g/L，钼酸铵质量浓度为37.5 g/L，酒石酸氧锑钾质量浓度为1.75 g/L，消解时间为30 min，为小体系海水TP测定新方法的最佳反应条件。通过正交验证及F与t检验，证明所建立的海水TP测定新方法与国标法的测定结果具有较高的拟合度。此外，TP测定新方法的浓度上限为28.8 μmol/L，与国标法相比，提高了4.5倍。新方法反应体系小，检测浓度范围广，能够减少检测过程中因梯度稀释步骤带来的误差，方法准确性高，为海水TP的测定提供了新的选择。     

大气中芳香胺及吡啶类化合物的离子色谱法测定

采用GDX-501富集大气中芳香胺及吡啶类化合物,经沸水解吸后解吸液直接注入离子色谱仪,用紫外/可见光检测器进行测定。方法灵敏、简便,可同时测定吡啶、2-甲基吡啶、3-甲基吡啶、苯胺、邻-甲苯胺、间-甲苯胺等。当采样体积为30L时,方法的最低检出浓度范围为0.05～0.10mg/m3(吡啶～间甲苯胺),测定的回收率为84.7%～95.9%,相对标准偏差为4.0%～6.6%。     

双道原子荧光同时测定海水中痕量砷和汞

建立了双道原子荧光同时测定海水中痕量砷和汞的方法。在试验条件下,砷和汞测定的相对标准偏差≤4．0％．加标回收率在92．0％～104％之间。方法操作简便,灵敏快速,适用于海水及其他水体中砷和汞的测定。     

气相分子吸收光谱法测定海水中的氨氮

采用气相分子吸收光谱法测定海水中的氨氮,并对相关影响因素进行探讨。结果证实,近海岸海水和河口水样品加酸固定后需调节pH值至中性;无须滤膜抽滤,可直接上机检测;所用溴酸盐混合储备液和40%氢氧化钠溶液在25℃保存不宜超过2周,超过25℃应现用现配;采集好的水样不宜长时间保存,应立即测定。方法在ρ(氨氮)为0.01~0.40 mg/L和0.10~2.00 mg/L范围内均具有良好的线性,r值均0.999;方法检出限为0.003 mg/L;实际样品和标准样品的RSD为1.0%~1.6%;加标回收率为94.0%~110%。与次溴酸盐氧化法相比,二者氨氮的测定结果无显著性差异,气相分子吸收光谱法测定氨氮的范围更宽,高浓度的氨氮样品可直接检测,减少稀释带来的误差。     

微波消解-原子吸收光度法测定土壤中铜锌铅镉镍铬

用微波消解－原子吸收光度法测定土壤中铜，锌，铅，镉，镍和铬。通过硝酸－氢氟酸－过氧化氢体系消解液对土壤样品消解，选择出微波最佳消解条件。对硝酸－盐酸－过氧化氢体系消解液和硝酸－氢氟酸－过氧化氢体系消解液进行消解对比试验，发现前者不能将土壤样品完全消解，后者能将样品消解完全，但需将消解液中剩余的酸赶尽，否则测定结果将明显偏低。微波消解土壤与传统电热消解相比，操作简便快速，可提高工作效率。     

Topsoil and Housedust Metal Concentrations in the Vicinity of a Lead Battery Manufacturing Plant

The aim of the study was to determine the extent of heavy metal pollution in the vicinity of a lead battery manufacturing plant in the Czech Republic, both in the general environment and within homes. Topsoils (0–5 cm) were sampled from 100 sites along 4 transects which crossed the battery factory, the town centre and outlying rural areas. Housedust samples were collected from 15 plant-workers' homes and 15 non plant-workers' homes located at various distances from the factory. Samples were analysed for levels of Pb, Zn, Cd, Cu, As and Sb, using ICP-AES. Soil concentrations of Pb, Cd, As and Sb peaked at the perimeter fence of the battery factory with Pb levels of up to 12 650 g g> ^-1. Concentrations of these metals decreased exponentially within 500 m of the plant. Whilst the battery factory does appear to be a source of all the metals with the exception of Zn, emissions do not appear to be transported to any great extent over distances of more than 0.5 km. Topsoil and housedust concentrations of Pb, Zn, Cd, Cu, As and Sb in the general Mlada Boleslav area do not appear to be significantly different from those recorded in a large scale survey of urban soils in the United Kingdom. A comparison of housedust Pb concentrations in homes of plant workers and non-plant workers suggests that there may be a small input of Pb into the home environment by battery plant employees.     

An Overview of Contaminant-Related Issues Identified by Monitoring in San Francisco Bay

The San Francisco Estuary Regional Monitoring Program for Trace Substances (RMP) began in 1993 and is sponsored by 74 local, state, and federal agencies and companies through their discharge or Bay use permits. The RMP monitors water, sediment, toxicity, and bivalve bioaccumulation at 25 sites in the Bay that are considered to represent "background" conditions. Several major environmental issues have been identified by the RMP. Polychlorinated biphenyls and mercury were often above water quality guidelines, and often occurred in fish tissues above U.S. Environmental Protection Agency (U.S. EPA) screening values. Concentrations do not appear to be decreasing, suggesting continuing inputs. Episodes of aquatic toxicity often occurred following runoff events that transport contaminants into the Bay from urbanized and agricultural portions of the watershed. Sediment toxicity occurred throughout the Bay, and has been correlated with concentrations of specific contaminants (chlordanes, polynuclear aromatic hydrocarbons) at some locations; mixtures of contaminants were probably also important. Since the RMP does not monitor all ecosystem components, assessments of the overall condition of the Bay cannot be made. However, in terms of contamination, the RMP samples suggest that the South Bay, and North Bay sites are moderately contaminated.     

Biomagnification factors (fish to Osprey eggs from Willamette River,Oregon, U.S.A.) for PCDDs,PCDFs, PCBs and OC pesticides

A migratory population of 78 pairs of Osprey (Pandion haliaetus) nesting along the Willamette River in westernOregon was studied in 1993. The study was designed to determinecontaminant concentrations in eggs, contaminant concentrationsin fish species predominant in the Ospreys diet, andBiomagnification Factors (BMFs) of contaminants from fish specieseaten to Osprey eggs. Ten Osprey eggs and 25 composite samplesof fish (3 species) were used to evaluate organochlorine (OC)pesticides, polychlorinated biphenyls (PCBs), polychlorinateddibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans(PCDFs). Mercury was also analyzed in fish. Geometric meanresidues in Osprey eggs were judged low, e.g., DDE 2.3 g g^-1 wet weight (ww), PCBs 0.69 g g^-1, 2,3,7,8-TCDD 2.3 ng kg^-1, and generally well below known threshold values for adverse effects on productivity, and the population was increasing. Osprey egg residue data presentedby River Mile (RM) are discussed, e.g., higher PCDDs were generally found immediately downstream of paper mills and eggsfrom the Willamette River had significantly elevated PCBs and PCDDs compared to reference eggs collected nearby in the CascadeMountains. Prey remains at nest sites indicated that the Largescale Sucker (Catostomus macrocheilus) and NorthernPikeminnow (Ptychocheilus oregonensis) accounted for an estimated 90.1% of the biomass in the Osprey diet, and composite samples of these two species were collected from different sampling sites throughout the study area for contaminant analyses. With the large percentage of the fishbiomass in the Osprey diet sampled for contaminants (and fisheaten by Ospreys similar in size to those chemically analyzed),and fish contaminant concentrations weighted by biomass intake, a mean BMF was estimated from fish to Osprey eggs for the largeseries of contaminants. BMFs ranged from no biomagnification(0.42) for 2,3,7,8-TCDF to 174 for OCDD. Our findings for themigratory Osprey were compared to BMFs for the resident HerringGull (Larus argentatus), and differences are discussed. Webelieve a BMF approach provides some basic understanding ofrelationships between contaminant burdens in prey species offish-eating birds and contaminants incorporated into their eggs,and may prove useful in understanding sources of contaminants inmigratory species although additional studies are needed.     

The Draft of the New German Guideline VDI 3782/8 to Model Automobile Exhaust Dispersion

The draft of the German guideline to calculate automobile exhaust dispersion is explained. It contains a two-stage-system: For first quick estimates the guideline contains the simple models MLuS and STREET. In case these models are not applicable or their results shows concentration levels close to the air quality standards, the more complex models PROKAS_V and MISKAM are recommended. PROKAS_V is a Gaussian plume model, MISKAM is a 3-dimensional microscale non hydrostatic flow model for built-up areas with an Eulerian dispersion model. The guideline comprises cases in rural areas without or with few adjacent buildings as well as urban areas with buildings near the roads. The contribution gives information about the models, typical results and some of the problems showing up presently.     

Hydrocarbon Utilization in Yeast Isolates Found to Grow in Association with Petroleum in a Polluted Ultisol of Midwestern Nigeria

The population counts of hydrocarbon-utilising yeasts weremonitored at six sampling stations in the Benin City municipalarea over a four-week period. Although the population countswere relatively constant in each locality, the highest countsoccurred in areas heavily polluted by domestic and industrialeffluents. A total of thirty-five hydrocarbon-degrading yeastswere isolated from soil at the sampling stations usingn-hexadecane as sole carbon source. The isolates were identifiedas belonging to the genera Candida (27 strains), Endomycopsis (4 strains). All the organisms grew on long-chainn-alkane, kerosene, diesel oil and crude oil but failed to growon short-chain n-alkane, aromatic and alicyclic hydrocarbons.Measurement of growth attributes of the isolates usingn-hexadecane, diesel oil and crude oil as substrates showed thatthe Candida species were better utilizers of hydrocarbonsubstrates relative to Endomycopsis and Schizosaccharomyces species.     

Hydrologic–Economic Model for Managing Irrigation Intensity in Irrigation Areas under Watertable and Soil Salinity Targets

This paper gives mathematical details and sample applications of SWAGMAN Farm (SWAGMAN, Salt Water and Groundwater Management), a farm-scale hydrologic economic model that integrates agronomic, climatic, irrigation, hydrogeological and economic aspects of irrigated agriculture. The model is capable of determining optimum mix of land use to keep watertable and soil salinity within acceptable limits while maximising the economic returns. Alternatively, the model can simulate water and salt balance and economics of a given cropping preference. Web-based and Geographic Information Systems versions of the model are available for integration with the environmental reporting systems of the irrigation areas.     

火焰原子吸收光谱法测定苏州开发区26种蔬菜中铜锌铁锰镍

用火焰原子吸收光谱法测定了苏州开发区26种蔬菜中的铜、锌、铁、锰和镍的含量。蔬菜样品用硝酸高氯酸混合酸进行消解。4次测定值的相对标准差<5%,加标回收率在92%～107%之间。26种蔬菜中铜、锌、铁、锰、镍的含量基本均在世贸组织规定的范围内。     

Using Multiple Taxonomic Groups to Index the Ecological Condition of Lakes

Biological indicators of communitiestypically reflect a common environmental signalreflecting the general condition of the ecosystem, as well asindividual signals by indicators differentiallysensitive to particular environmental conditions. Wedescribe here a method of integrating and interpretingsuch indicators from 19 New England lakes for fivetaxonomic groups (diatoms, benthos, zooplankton, fish,and birds). Our approach provides a systematicstandardized way to integrate multiple metrics fromdifferent taxonomic groups by addressing four elementscrucial to analyzing data from multiple indicators: covariate control, re-scaling of data, standardizing the sign of responses, and dimensional reduction. We evaluated the biologicalmetrics against individual environmental stressors andagainst multivariate physicochemical metricscharacterizing general anthropogenic stress among thelakes. The method detected a response to variationin the gross environmental condition of the lakes thatwas correlated across taxa and metrics. In addition,a differential response to near shore conditions wasdemonstrated for fish. The success of the approach inthis study lends support to its general application toecological monitoring involving complex data sets.     

Concentrations of Cadmium, Mercury and Selenium in Blood, Liver and Kidney of Common Eider Ducks from the Canadian Arctic

We determined concentrations of selected trace elements inlivers, kidneys and blood samples from common eiders (Somateria mollissima borealis) from the eastern Canadianarctic during 1997 and 1998. Concentrations of totalmercury and organic mercury were generally low in the liversof these birds (less than 6 and 4 g g^–1 dry wt,respectively). Selenium ranged between 11–47 g g^–1 inlivers. Renal cadmium concentrations were among the highestever published for this species (range: 47–281 g g^–1). The regressions of log-transformed concentrations ofthese trace elements in blood samples on those in liver orkidney were significant (all P-values < 0.05) andpositive. However, except for organic mercury (RM ² = 0.83), the co-efficients of determination were low tomoderate (range of R ²: 0.26–0.52), suggesting poorto moderate predictive capability. Furthermore, therelationships between total mercury in blood and liverchanged between 1997 and 1998, suggesting that it would notbe possible to predict consistently, concentrations ofmercury in blood from those in liver based on samples takenin one year. Blood samples can be used to determineconcentrations of these trace elements in common eiders (andprobably other sea duck species as well). The use of bloodsamples is especially warranted when it is undesirable tokill the animal such as when working with rare or endangeredsea duck species or when the objective is to relate traceelement exposure to annual survival rates. However, thepredictive equations developed here should not be used topredict expected concentrations in one type of tissue fromthose in the other.